New from CO

[Albm12737]

Howdy!!

 

[enysse]

Welcome to AH, those are some interesting guns you own. I had to look up .256 Newton caliber.

 

[krish]

Welcome to AH.
KRISH

 

[AncientMariner]

Welcome to AH, those are some interesting guns you own. I had to look up .256 Newton caliber.

An avid Jack O'Connor fan back in the day, it struck me that the .256 Newton probably had a similar bore capacity to the .270 Winchester, which Jack claimed to be ideal. It very much seemed to me to be a cartridge that shouldn't have died. In the early '70's, I had to pass on a $220 Buffalo Newton that would have come with Belding & Mull press and a couple of boxes of ammo. My vacation was running out and so were my funds. It was time to go back to sea and I knew that a domestic war would ensue if I yielded to this temptation. The pain of that loss was finally resolved a few years after I moved to Colorado in 2013. No longer had anyone to make excuses to and I was retired. It felt like settling a score. The gent who rebarreled the M77 for me made a .256 for himself, while he was at it. Not sure what action he used. He's obviously a kindred spirit in thinking that the Newton is a viable cartridge in the 21st century.

 

[enysse]

Thanks for the explanation! I think years ago I got tempted by speed, flat shooting calibers. I bought a 7 mm Ultra Mag and a 270 WSM. Times have changed and now I’m interested in how the hunt is carried out. I want a close encounter with animals rather than shooting from more than 300 yds away.

 

[AncientMariner]

Thanks for the explanation! I think years ago I got tempted by speed, flat shooting calibers. I bought a 7 mm Ultra Mag and a 270 WSM. Times have changed and now I’m interested in how the hunt is carried out. I want a close encounter with animals rather than shooting from more than 300 yds away.

My 20-inch barreled 9X57 is well suited to that. Frankly, I am more a theoretical hunter than an actual one. Several hunting rifles but few hunting outings. My pathetic collection of antlers is meager at best.

 

[Just Gina]

to AH!

 

[Jason Miller]

Welcome ! I also live in the Springs (part of the year)

 

[fourfive8]

Welcome to AH

Ackley was one heckuva gun crank and experimenter, just don't use his load data!

Try to find and use published data that takes into account the max pressure limit of about 46K CUP recommended for the M93 and M95 actions. Use a chronograph. Use common bullet weights for the calibers and powders that show the lowest pressures for working up to the objective velocities.

I have an M95 in 7x57. I use mid-range powders and set my objective velocity at about 2300 fps for the 175 grain bullet. I am 100% confident in the load and experience zero problems. After all, WDM Bell killed 1000+ elephants with a FMJ 173 gr bullet at about 2300 fps out of his 7x57.

Flattened primers can be caused by either excess headspace or excess pressure (or both). After fire forming brass in your chamber, set your sizing die to minimally resize cases so the case shoulder barely clears contact with the chamber's shoulder when a round is chambered. This minimizes introdrodution of excess headspace and will increase case life. That way flattened primers become more diagnostic of excess pressure.

 

[Andrew62]

Welcome, certainly glad to have you be a part of this great community!

 

[AncientMariner]

Welcome to AH

Ackley was one heckuva gun crank and experimenter, just don't use his load data!

Try to find and use published data that takes into account the max pressure limit of about 46K CUP recommended for the M93 and M95 actions. Use a chronograph. Use common bullet weights for the calibers and powders that show the lowest pressures for working up to the objective velocities.

I have an M95 in 7x57. I use mid-range powders and set my objective velocity at about 2300 fps for the 175 grain bullet. I am 100% confident in the load and experience zero problems. After all, WDM Bell killed 1000+ elephants with a FMJ 173 gr bullet at about 2300 fps out of his 7x57.

Flattened primers can be caused by either excess headspace or excess pressure (or both). After fire forming brass in your chamber, set your sizing die to minimally resize cases so the case shoulder barely clears contact with the chamber's shoulder when a round is chambered. This minimizes introdrodution of excess headspace and will increase case life. That way flattened primers become more diagnostic of excess pressure.

Good info. My FN Supreme 7X57 has excessive headspace. I hadn't used it in so long that I forgot that and was puzzled by cratered primers that were still rounded with what should have been mild loads. I imagined a too long firing pin, among other unlikely scenarios. Gunsmith checked headspace and told me what I certainly should have remembered. No recurrence since paying attention to head to shoulder datum of 7X57 cases.

The new to me 8X60S has much more rattle room, to the point that I'm making a little shoulder to facilitate fire forming. So far, so good. The little shoulder bump compresses on bolt closure but is enough to hold against firing pin impact on the primer.

I have an ample supply of brass for the FN. If I needed to use new brass, I'd use the 8mm expander ball to swell the neck enough for a fireforming bump. I used a headspace comparator just larger than neck dia of fired 8X60 cases and learned to size expanded necks to about 0.003" longer than that for a satisfying amount of torque to close the bolt. Case length grew not at all upon firing. Unmodified new cases grew dramatically. I discarded those.

 

[MATTANJA HUNTING SAFARIS]

Welcome to AH!

 

[fourfive8]

@AncientMariner, that's a good approach. One problem with obsolete cartridges in older rifles is finding decent published load data. One source is "Cartridges of the World". It has load data and other pertinent info for most cartridges but as with any, proceed with caution. I constantly use my old 8th Edition for cross reference and comparison.

 

[AncientMariner]

@AncientMariner, that's a good approach. One problem with obsolete cartridges in older rifles is finding decent published load data. One source is "Cartridges of the World". It has load data and other pertinent info for most cartridges but as with any, proceed with caution. I constantly use my old 8th Edition for cross reference and comparison.

View attachment 507789

Right on. I have the 3rd, 6th, and 12th editions. Load data is generally sparse, but a good starting point. I do wish that their measurement chapter included water capacities.

 

[elk6024]

Welcome to AH